Adjustable air flow damper for a luminaire



April 4, 1967 QE. RACKLEY ADJUSTABLE AIR FLOW DAMPER FOR A LUMINAIRE Filed Dec. 5o, 1965 N# Nmmwm E wir f, J

United States Patent Oflice 3,3 12,1 Patented Apr. 4, 1 967 3,312,160 v ADJUSTABLE AIR FLW DAMPER FOR A LUMINAIRE Carle E. Rackley, Westlake, Ohio, assigner to Westinghouse Electric Corporation, Pittsburgh, Pa., a corporation of Pennsylvania Filed Dec. 30, 1965, Ser. No. 517,659 7 Claims. (Cl. 98-40) This invention relates generally to air-handling luminaires and, more particularly, to the dampers provided in these luminaires for controlling the air flow therethrough. It is known to provide air exit ports in luminaire housings by cutting around three sides Iof the air port and bending the tab thus formed away from the luminaire housing to form an air port. The bent tab portion forms a partial cover over the air port. If the tab cover is bent outwardly too far, a considerable portion of the air port is exposed from above and dirt, dust, or foreign matter may fall therethrough into the luminaire. If the tab 'cover' is not bent enough, this dirt problem is partially solved, but the air port then has an intolerable impedance to air flow because the tab cover is not far enough away trom the air port.

It is'therefore an object of this invention to provide a novel adjustable air ow damper for a luminaire housing.

' It is a further object of this invention to provide an exit air ow damper which hinders the passage of foreign matter falling therethrough.

It is another object of this invention to provide an air ow damper having improved air ilow therethrough.

i Briey, these and other objects are achieved by providing an adjustable damper member slidably mounted over a set of air exit ports provided in the luminaire housing. The' damper member has an additional set of air exit ports. The overlap between the two sets of air ports may be ladjusted to control the flow of air through the luminaire. The damper member has raised cover portions positioned `over the air ports to prevent foreign matter from falling directly into the luminaire from above. The air port covers are axed to the damper along the periphery of the ai'r ports. This. joining includes only a minor portion of the air port periphery, leaving the remainder of the periphery free of obstacles for passing air. The covers are raised above the air ports a suflicient distance so as not to impede the ow of air therethrough.

Further objects and advantages of this invention Will become apparent as the features of novelty which characterize the invention are pointed Iout in more particularity in the following detailed description.

For a better understanding of the invention reference may be had to the accompanying drawings wherein:

FIGURE l shows a sectional elevation of an installed luminaire taken along the line I-I of FIG. 2;

FIG. 2 shows an elevational side view, partly in section;

FIG. 3 shows a fragmentary isometric view of a portion of the luminaire top member With the adjustable damper shown in the exploded form;

FIG. 4 shows a sectional elevation of a portion of the adjustable damper in the full open position taken -along line IV-IV of FIGURE l; and

FIG. 5 shows the adjustable damper of FIG. 4, but in the half-open position. v

Referring now to FIGURE 1, there is shown a luminaire having a housing 12 formed by top member 14, side walls 16, and end walls 18. The side walls 16 define a bottom light opening 2t) over which is dispos-ed an at least partially light transmitting closure member or refractor 22. The housing 12 and refractor 22 form an enclosure 24 in which is contained lampholders 26 and heat generating light sources or fluorescent lamps 28 secured therein. In order to remove at least a part of the heat generated by the light sources 28 and to provide `a path for air return, an air entrance slot 30 is provided along at least one edge `of the refractor 22. This entrance slot 30 and the air flow through the luminaire 10 is more clearly shown in FIG. 2. The air flow leaves the luminaire 10 through a plurality of generally parallel air exit slots 32 provided in a portion of the top member 14. Bridge portions 34 extend between adjacent housing exit slots 32. The rate of air ow is controlled by adjustable damper 40 which is po-sitioned exterior to the luminaire 12 proximate that portion of the top member 14 which is provided with the housing exit slots 32.

Referring to FIG. 3, the construction of the adjustable damper 40 is clearly shown. The damper 40 has a generally planar base -portion 42 through which is provided a plurality of generally parallelly disposed air exit slots 44. Bridge portions 46 are provided between the adjacent damper exit slots 44. The damper exit slots 44 and bridge portions 46 generally correspond in shape and spacing to the housing exit slots 32 and bridge portions 34. Each damper exit slot 44 is provided with a raised cover 48 positioned directly thereover. The spaced covers 48 are aixed t-o the base 42 at each end of the corresponding damper exit slots 44. This construction forms plural air passages through the overlapping exit slots 32 and 44 and around both edges of the corresponding cover 48. If preferred, the damper 40 may have upturned edges for forming reinforcing ribs 45 as shown in FIG. 3. If preferred, the entire damper 4t) may be stamped from a single piece lof sheet metal to form a single unitary damper 40.

The under surface of the damper 4t) engages the upper surface of the top member 14 and is limitedly slidable thereacross. This'sliding movement permits the adjustment of the overlying between the housing exit slots 32 and the damper exit slots 44 to control the rate of ow of air through the luminaire 10. This sliding movement is limited by a pair of elongated apertures 50 provided in the top member 14 proximate the housing exit slots 32. The longitudinal dimension of the apertures 50 is oriented parallel to the direction of sliding, and generally perpendicular to Ithe longitudinal dimensions of the exit slots 32 and 44. In order to releasably secure the damper 40 to the top member 14, a screw means 52 extends upwardly through each of the elongated apertures 50. Preferably, these screws 52 may be loosened from the underside of the top member 14.

The damper 40 is slidable from a full open position shown in FIG. 4 to a full closed position. In the full open position, maximum air flow through the luminaire 10 is permitted because the housing exit slots 32 and the damper exit slots 44 fully overlie. In this position, the housing bridge portions 34 and the damper bridge portions 40 fully overlap and continuously engage. In the full closed position, substantially no air flow is permitted through luminaire 10 because the exit slots 32 and 44 are blocked by the overlapping -of the adjacent damper bridge portions 46 and the housing bridge portions 34, respectively. FIG. 5 shows the damper 40 in a partially open position intermediate between the full open position shown in FIG. 4 and the full closed position described above. In the partially lopen position, the exit slots 32 and 44 partially overlap to permit an intermediate rate of tlow of the air through the luminaire.

As can be seen in FIG. 4, the housing exit slots 32 are slightly smaller than the corresponding damper exit slots 44. The edges of the housing air slots 32 slightly overlap the damper Iair slots 44 to additionally prevent foreign matter, such as dirt and dust, from vertically falling through the overlying exit slots 32 and 44 into the luminaire enclosure 24.

The cover portions 48 are positioned directly over the damper exit slots 44 to prevent dust, dirt, and foreign matter from falling from above through the overlapping exit slots 32 yand 44 and into the luminaire enclosure 24. The slots 32 and 44 are exit slots and the air flow therethrough from the luminaire enclosure 24 into the rafter or duct area above the luminaire further :prevents foreign matter from entering the luminaire i0.

The cover portions 48 are raised above the damper exit slots 44 a vertical distance which is at least one-half of the width dimension of the housing exit slots 32.

It will be apparent to those skilled in the art that the objects of this invention have been achieved by providing ta damper having cover portions which are disposed directly over the air slots therein. The positioning of the cover prevents foreign matter from falling directly into the luminaire. The cover portions are positioned far enough away from the air slots so as not to impede the air ow therethrough. Further, the covers are attached to the luminaire only `at the ends of the air slots to permit full flow of the air through the ai-r slots and around both edges of the cover portions.

Although this invention has been described with respect to a particular embodiment thereof, it is not to be so limited as changes and modications may be made therein which are Within the intended scope of the invention.

I claim as my invention:

1. An air-handling luminaire comprising:

a housing having a top member and walls aixed thereto, a bottom light opening generally dened by said walls;

1an at least partially light transmitting closure member disposed within said bottom opening and forming an enclosure with said housing;

lampholder means mounted on said housing and adapted to support heat generating light-source means Within said enclosure;

said enclosure having an air entrance means provided along at least one edge of said light transmitting closure member;

a portion of said housing top member `having a plurality of air exit slots arranged generally parallel with one another with bridge portions formed therebetween;

a unitary adjustable damper positioned exterior to said housing, said damper comprising a generally planar damper base portion and a plurality of raised spaced damper cover portions;

said damper base portion provided with a plurality of generally parallel air exit slots and bridge portions which generally correspond in shape and spacing to the exit slots and bridge portions provided in said housing top member, said bridge portions of said housing top member and said bridge portions of said damper base portion contiguously and slidably engaging to permit the adjustment of overlie between the exit slots in said housing top member and the exit slots in said damper base portion;

said damper cover portions raised a predetermined distance directly `over and covering the air exit slots provided in said damper base portion to prevent foreign matter from falling through the overlying exit slots provided in said damper base portion and in said housing top member into said enclosure formed within said luminaire; and

means for permitting limited slidable movement of said damper on said housing top member from a full open position where the slots provided in said damper base portion substantially overlie the slots provided in said housing top member to a full closed position where the slots provided in said housing top member are substantially overlapped by said bridges in said damper base portion.

2. The luminaire as speciied in claim 1, wherein the air exit slots provided in said housing top member are slightly smaller than the ycorresponding air exit slots provided in said damper base portion.

3. The luminaire `.as specified in claim 1, wherein said raised spaced damper cover portions are afxed to said damper base portion at each end of the corresponding air exit slots provided in said damper base portion to form piural air passages through each of the air exit slots provided in said damper base portion and around both edges of each of said raised spaced damper cover portions.

4. The luminaire as specified in claim 3 wherein the vertical distance between said raised spaced damper cover portions and air exit slots provided in said damper base portion is at least equal to one half of the width dimension of the air exit slots provided in said housing top member.

5. The luminaire as specitied in claim 3, wherein said damper base portion has an upwardly extending reinforcing rib portion along the opposed edges thereof which are generally parallel to the limited slidable movement of said damper member.

6. The luminaire as specified in claim 3, wherein said means for providing limited slidable movement comprises a pair of elongated apertures provided in said housing top member proximate the air exit slots provided therein and disposed parallel to the direction of the limited slidable movement of said damper member, and means engaging said damper member and extending downwardly through the elongated aperture provided in said top member for releasably securing said housing top member to said damper member.

7. The luminaire as specified in claim 6, wherein the pair of elongated apertures provided in said housing top member are disposed perpendicular to the air exit slots provided in said housing top member.

References Cited by the Examiner UNTT ED STATES PATENTS 9/1963 Quin 98-40 7/1966 Bradley et al. 98--40 

1. AN AIR-HANDLING LUMINAIRE COMPRISING: A HOUSING HAVING A TOP MEMBER AND WALLS AFFIXED THERETO, A BOTTOM LIGHT OPENING GENERALLY DEFINED BY SAID WALLS; AN AT LEAST PARTIALLY LIGHT TRANSMITTING CLOSURE MEMBER DISPOSED WITHIN SAID BOTTOM OPENING AND FORMING AN ENCLOSURE WITH SAID HOUSING; LAMPHOLDER MEANS MOUNTED ON SAID HOUSING AND ADAPTED TO SUPPORT HEAT GENERATING LIGHT-SOURCE MEANS WITHIN SAID ENCLOSURE; SAID ENCLOSURE HAVING AN AIR ENTRANCE MEANS PROVIDED ALONG AT LEAST ONE EDGE OF SAID LIGHT TRANSMITTING CLOSURE MEMBER; A PORTION OF SAID HOUSING TOP MEMBER HAVING A PLURALITY OF AIR EXIT SLOTS ARRANGED GENERALLY PARALLEL WITH ONE ANOTHER WITH BRIDGE PORTIONS FORMED THEREBETWEEN; A UNITARY ADJUSTABLE DAMPER POSITIONED EXTERIOR TO SAID HOUSING, SAID DAMPER COMPRISING A GENERALLY PLANAR DAMPER BASE PORTION AND A PLURALITY OF RAISED SPACED DAMPER COVER PORTIONS; SAID DAMPER BASE PORTION PROVIDED WITH A PLURALITY OF GENERALLY PARALLEL AIR EXIT SLOTS AND BRIDGE PORTIONS WHICH GENERALLY CORRESPOND IN SHAPE AND SPACING TO THE EXIT SLOTS AND BRIDGE PORTIONS PROVIDED IN SAID HOUSING TOP MEMBER, SAID BRIDGE PORTIONS OF SAID HOUSING TOP MEMBER AND SAID BRIDGE PORTIONS OF SAID DAMPER BASE PORTION CONTINGUOUSLY AND SLIDABLY ENGAGING TO PERMIT THE ADJUSTMENT OF OVERLIE BETWEEN THE EXIT SLOTS IN SAID HOUSING TOP MEMBER AND THE EXIT SLOTS IN SAID DAMPER BASE PORTION; SAID DAMPER COVER PORTIONS RAISED A PREDETERMINED DISTANCE DIRECTLY OVER AND COVERING THE AIR EXIT SLOTS PROVIDED IN SAID DAMPER BASE PORTION TO PREVENT FOREIGN MATTER FROM FALLING THROUGH THE OVERLYING EXIT SLOTS PROVIDED IN SAID DAMPER BASE PORTION AND IN SAID HOUSING TOP MEMBER INTO SAID ENCLOSURE FORMED WITHIN SAID LUMINAIRE; AND MEANS FOR PERMITTING LIMITED SLIDABLE MOVEMENT OF SAID DAMPER ON SAID HOUSING TOP MEMBER FROM A FULL OPEN POSITION WHERE THE SLOTS PROVIDED IN SAID DAMPER BASE PORTION SUBSTANTIALLY OVERLIE THE SLOTS PROVIDED IN SAID HOUSING TOP MEMBER TO A FULL CLOSED POSITION WHERE THE SLOTS PROVIDED IN SAID HOUSING TOP MEMBER ARE SUBSTANTIALLY OVERLAPPED BY SAID BRIDGES IN SAID DAMPER BASE PORTION. 